Abstract
ISCOMs have received much attention as vaccine adjuvants due to their immunostimulatory effects. They are colloidal particles typically comprised of phospholipids, cholesterol and Quil A, a crude mixture of saponins extracted from the bark of Quillaja saponaria Molina. We have previously shown that ISCOMs can be prepared by ether injection wherein an ether solution of phospholipids and cholesterol in a mass ratio of 5:2 is injected into a solution of Quil A at a mass ratio of 7 lipids: 3 Quil A. The aim of this study was firstly to isolate and characterise discrete fractions of Quil A and secondly to investigate which of these fractions were able to form ISCOMs by the method of ether injection. Six fractions of Quil A were isolated by semi-preparative reverse phase high performance liquid chromatography (RP-HPLC) and characterised by analytical HPLC, liquid chromatography tandem mass spectrometry (LC-MS) and the qualitative Liebermann- Burchard and Molisch tests for triterpenoids and carbohydrates respectively. ISCOMs were subsequently prepared from the isolated fractions by the method of ether injection and the resulting preparations characterized by photon correlation spectroscopy (PCS) and negative stain transmission electron microscopy (TEM). The molecular weights of the major compounds in the fractions ranged from ∼1200 to ∼2300 Da; all fractions tested positive for triterpenoids and saccharides and four of the fractions were identified as QS-7, QS-17, QS-18 and QS-21 by analysis (LC-MS and analytical HPLC). Injection of ether solutions of lipids into aqueous solutions of QS-17, QS-18 or QS-21 all resulted in homogeneous ISCOM dispersions. The combination of lipids and QS-7 by ether injection produced lamellae and liposomes as the prominent structures and a minor amount of ISCOMs. The remaining two hydrophilic, low molecular weight fractions of Quil A did not produce ISCOMs, instead liposomes and helical structures predominated in the samples.
Keywords: ISCOM, Immuno-stimulating complex, Quil A, ether injection, drug delivery, vaccine delivery
Call for Papers in Thematic Issues
Advances of natural products, bio-actives and novel drug delivery system against emerging viral infections
Due to the increasing prevalence of viral infections and the ability of these human pathogens to develop resistance to current treatment strategies, there is a great need to find and develop new compounds to combat them. These molecules must have low toxicity, specific activity and high bioavailability. The most suitable ...read more
Electrospun Fibers as Drug Delivery Systems
In recent years, electrospun fibers have attracted considerable attention as potential platforms for drug delivery due to their distinctive properties and adaptability. These fibers feature a notable surface area-to-volume ratio and can be intentionally designed with high porosity, facilitating an increased capacity for drug loading and rendering them suitable for ...read more
Emerging Nanotherapeutics for Mitigation of Neurodegenerative Disorders
Conditions affecting the central nervous system (CNS) present a significant hurdle due to limited access of both treatments and diagnostic tools for the brain. The blood-brain barrier (BBB) acts as a barrier, restricting the passage of molecules from the bloodstream into the brain. The most formidable challenge facing scientists is ...read more
Nanotechnology Based Chemotherapy for the treatment of Head & Neck Cancer
The escalating recurrence rates observed in Head and Neck cancer, particularly within the chemo-therapeutically treated cohort (50-60%), can be attributed to the non-selective nature of current anticancer drug delivery modalities. In this context, nanotechnology-based drug delivery systems emerge as a promising avenue for achieving precise localization of therapeutic agents to ...read more
Related Journals
Anti-Cancer Agents in Medicinal Chemistry
Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry
Current Bioactive Compounds
Current Cancer Drug Targets
Combinatorial Chemistry & High Throughput Screening
Current Cancer Therapy Reviews
Current Diabetes Reviews
Current Drug Safety
Current Drug Targets
Current Drug Therapy
Related Books
Drug Addiction Mechanisms in the Brain
Software and Programming Tools in Pharmaceutical Research
Objective Pharmaceutics: A Comprehensive Compilation of Questions and Answers for Pharmaceutics Exam Prep
Biotechnology and Drug Development for Targeting Human Diseases
Medicinal Chemistry of Drugs Affecting Cardiovascular and Endocrine Systems
Enzymatic Targets for Drug Discovery Against Alzheimer's Disease
Medicinal Plants, Phytomedicines and Traditional Herbal Remedies for Drug Discovery and Development against COVID-19
Advanced Pharmacy
Plant-derived Hepatoprotective Drugs
Brain Tumor Targeting Drug Delivery Systems: Advanced Nanoscience for Theranostics Applications
24